1. Field of the Invention
This application relates to a semiconductor memory.
2. Description of Related Art
A pseudo-SRAM includes DRAM memory cells and SRAM interfaces and automatically performs refresh operations of the memory cells in a chip. In a pseudo-SRAM, refresh requests generated within a chip are generated asynchronously with an external access requests. Techniques related to the pseudo-SRAM are disclosed in Japanese Laid-open Patent Publication No. 2005-285271, Japanese Laid-open Patent Publication No. 2007-12244 or the like.